Climate Change Leaves Hares Wearing The Wrong Colors

The effects of climate change often happen on a large scale, like drought or a rise in sea level. In the hills outside Missoula, Mont., wildlife biologists are looking at a change to something very small: the snowshoe hare.

Life as snowshoe hare is pretty stressful. For one, almost everything in the forest wants to eat you.

Alex Kumar, a graduate student at the University of Montana, lists the animals that are hungry for hares.

They catch other hares with wire traps about the size of a breadbox, with some apple as bait. Most of the hares they track live less than a year — a hazard of being what Kumar calls “the cheeseburger of the ecosystem.”

But snowshoe hares have a trick up their sleeve: camouflage. They’re brown during the summer, but turn stark white for the snowy winter months. Kumar says it works.

“There’s times when you’re tracking them and you know they’re really, really close, and you just can’t find them,” he says.

Hares switch colour in the spring and fall in response to light, when the days get longer or shorter. But that means they’re at the mercy of the weather. If the snow comes late, you get a white hare on brown ground.

“And they really think that they’re camouflaged,” Kumar says. “They act like we can’t see them. And it’s pretty embarrassing for the hare.”

Kumar calls this “mismatch,” and it’s becoming more of a concern with climate change.

“If the hares are consistently molting at the same time, year after year, and the snowfall comes later and melts earlier, there’s going to be more and more times when hares are mismatched,” he says.

Scott Mills of North Carolina State University leads the research. He says they’re finding that mismatched hares die at higher rates. That’s a concern for the threatened Canada lynx, which mainly eats these hares.

“It’s a picture that paints a thousand words,” Mills says. “It’s a very clear connection to a single climate change stressor.”

Mills says hares might be able to adapt over time. Some snowshoe hares in Washington State don’t turn white at all. Mills is trying to figure out whether hares and other wildlife can adapt as fast as the climate is changing.

“But really what we don’t know very well is how fast is too fast?” he says.